Method and Apparatus for Detecting Optical Network Unit, and Passive Optical Network System

ABSTRACT

Embodiments of the present invention disclose a method and an apparatus for detecting an ONU, and a passive optical network system. The method includes detecting an identity code of an ONU in an open uplink empty window or an empty timeslot, and determining that an ONU corresponding to the identity code of the ONU is a rogue ONU according to the identity code of the ONU. A corresponding apparatus and passive optical network system are also provided in the embodiments of the present invention. In the passive optical network system, a rogue ONU is detected and determined quickly and efficiently, and an effect on an uplink service is reduced.

This application is a continuation of International Patent ApplicationNo. PCT/CN2012/073243, filed on Mar. 29, 2012, which claims priority toChinese Patent Application No. 201110077143.9, filed on Mar. 29, 2011,both of which are hereby incorporated herein by reference in theirentireties.

TECHNICAL FIELD

The present invention relates to the field of communications, and inparticular, to a method and apparatus for detecting an optical networkunit, and a passive optical network system.

BACKGROUND

When a PON (passive optical network) is accessed, an OLT (optical lineterminal) at a central office is corresponding to more than one ONU(optical network unit) or ONT (optical network terminal). Because an ONTmay be regarded as a special ONU, the ONU is uniformly used in thefollowing in this specification.

In a downlink direction, downlink information of the OLT is uniformlysent to all ONUs through a fixed downlink optical wavelength; and in anuplink direction, all ONUs emit light at a specific timeslot accordingto a rule of an uplink optical channel bandwidth of time divisionmultiplexing. That is, the ONU emits uplink light according to abandwidth allocation indication of the OLT. However, a rogue ONU is anONU that emits light not according to the bandwidth allocationindication of the OLT.

There are many kinds of rogue ONUs. From the perspective of lightemission time of rogue ONUs, rogue ONUs may be divided into:persistent-emission rogue ONUs: ONUs that emit light anytime; andnon-persistent rogue ONUs: ONUs that emit light in a time segment thatis not indicated by the OLT, namely, ONUs that may emit light beforehandor may be shut down in delay.

As regards whether a rogue ONU accepts control of an OLT, rogue ONUs maybe divided into malicious rogue ONUs: rogue ONUs that do not respond toa control command of the OLT; and non-malicious rogue ONUs: rogue ONUsthat respond to the control command of the OLT.

As regards whether a rogue ONU is pre-configured, rogue ONUs may bedivided into pre-configured rogue ONUs: rogue ONUs that are addedthrough a network management system or a command line and have workedproperly, and are legal ONUs; and illegally accessing rogue ONUs: rogueONUs that are not approved by an administrator and are newly accessingONUs, and are also called rogue ONUs in an automatic discovery state.

Currently, at the time of detecting a rogue ONU, an OLT needs to open anuplink empty window first (namely, commands all ONUs not to emit light)to detect whether a rogue ONU exists. If a rogue ONU exists, the OLTinstructs all ONUs to power off their own optical module, and thenpowers on an optical module of each ONU one by one and opens an uplinkempty window for each ONU to separately detect and determine which ONUis a rogue ONU.

In the process of implementing the present invention, the inventor findsthat the prior art has at least the following problems:

With the foregoing detection method, an uplink empty window needs to beopened for all ONUs one by one for detection, and detection efficiencyis lower; and at the time of detection, transmission power supply ofONUs need to be shut down one by one, thus affecting an uplink serviceof an ONU.

SUMMARY OF THE INVENTION

The embodiments of the present invention aim to provide a method andapparatus for detecting an ONU, and a passive optical network system, soas to improve efficiency and accuracy of detecting a rogue ONU andreduce an effect on an uplink service.

An embodiment of the present invention provides a method for detectingan ONU, and the method includes detecting an identity code of an ONU inan open uplink empty window or an empty timeslot; and according to theidentity code of the ONU, determining that an ONU corresponding to theidentity code of the ONU is a rogue ONU.

An embodiment of the present invention further provides an ONU, and theONU includes an optical module, where the optical module includes anobtaining unit, configured to obtain an identity code of an ONU and asending unit, configured to send the identity code of the ONU, where theidentity code of the ONU is obtained by the obtaining unit, so that anOLT can detect the identity code of the ONU in an open uplink emptywindow or an empty timeslot.

An embodiment of the present invention further provides an OLT, and theOLT includes a detecting module, configured to detect, in an open uplinkempty window or an empty timeslot of the OLT, whether an identity codeof an optical network unit (ONU) is received and a processing module,configured to, when the detecting module detects the identity code ofthe ONU, determine that an ONU corresponding to the identity code of theONU is a rogue ONU.

An embodiment of the present invention further provides a passiveoptical network system, which includes an optical line terminal (OLT)and at least one optical network unit (ONU), where the optical networkunit (ONU) includes an optical module.

The optical module is configured to obtain an identity code of an ONU,and send the identity code of the ONU.

The OLT is configured to receive the identity code of the ONU in an openuplink empty window or an empty timeslot, and according to the identitycode of the ONU, determine that an ONU corresponding to the identitycode of the ONU is a rogue ONU.

Through the ONU detection method, apparatus and system in theembodiments of the present invention, the identity code of the ONU isdetected in the open uplink empty window or the empty timeslot; andaccording to the identity code of the ONU, the ONU corresponding to theidentity code of the ONU is determined as a rogue ONU, so that a rogueONU is detected and determined quickly and efficiently, and meanwhile,the effect on the uplink service is reduced.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present invention, and theadvantages thereof, reference is now made to the following descriptionstaken in conjunction with the accompanying drawings, in which:

FIG. 1 is a schematic flowchart of a method for detecting an ONUaccording to an embodiment of the present invention;

FIG. 2 is a schematic diagram of an open uplink empty window and anempty timeslot according to an embodiment of the present invention;

FIG. 3 is a schematic structural diagram of an ONU according to anembodiment of the present invention;

FIG. 4 is a schematic structural diagram of an OLT according to anembodiment of the present invention; and

FIG. 5 is a schematic structural diagram of a passive optical network(PON) system according to an embodiment of the present invention.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

To make the foregoing objectives, features and merits of the presentinvention clearer and more understandable, the embodiments of thepresent invention are described in further detail in the following withreference to the accompanying drawings and specific implementationmanners.

An ONT may be regarded as a special ONU. Therefore, only an ONU is takenas an example for description in this application. Those skilled in theart may understand that any embodiment that is applicable to the ONU inthis application is also applicable to the ONT.

Embodiment 1

This embodiment provides a method for detecting an ONU. As shown in FIG.1, the method includes:

S102: An optical line terminal (OLT) detects an identity code of anoptical network unit (ONU) in an open uplink empty window or an emptytimeslot.

The identity code of the optical network unit (ONU) is pre-configuredand sent by an optical module of the ONU; or, the identity code of theoptical network unit (ONU) is obtained and sent by the optical module ofthe ONU from a control module of the ONU within unauthorized time.

The identity code of the ONU is a specific sequence optical channel codethat identifies the ONU. The identity code of the ONU is configured by asystem, and may also be a product code of the optical module.Specifically, the identity code of the ONU may be a specific sequenceoptical channel code that identifies the ONU (may also be called aspecific code stream sequence of the ONU). The specific sequence opticalchannel code of the ONU may be formed by a delimiter plus a specificcode. The specific code may be any one or a combination of an LLID(logic link identifier), an ONU ID (ONU identifier), an SN (sequencenumber), a MAC code, a product code of the optical module, and a uniqueidentity that is allocated by the OLT to each ONU. ONUs connected withthe same OLT have different identities for distinguishing each ONU.

S104: According to the identity code of the ONU, the OLT determines thatan ONU corresponding to the identity code of the ONU is a rogue ONU.

The rogue ONU is a faulty ONU, that is, may be understood as an ONU thatemits light not according to a bandwidth allocation indication of theOLT.

A process of obtaining the identity code of the optical network unit(ONU) in S102 is specifically described in the following.

The ONU in this embodiment includes a control module and an opticalmodule. The control module may be an MAC module or an MAC chip.

After the ONU obtains the identity code of the ONU, once the opticalmodule in the ONU is faulty and uncontrollable, the identity code of theONU is sent. In this way, the OLT may detect the identity code of theONU in the open uplink empty window or the empty timeslot, andtherefore, judges that a rogue ONU exists, and may determine that theONU corresponding to the identity code of the ONU is a rogue ONU. Thatis, the rogue ONU is detected accurately without affecting normaltransmission of an uplink service. The optical module may obtain theidentity code of the ONU in two ways:

(1) The optical module of the ONU obtains the identity code of the ONUfrom an MAC module (or an MAC chip) within unauthorized time.

When the optical module of the ONU is controlled by the MAC module, theMAC module generally controls a Tx_ENABLE enable signal and a datasignal of the optical module, where TX_ENABLE means that the opticalmodule is enabled to emit light, and the data signal refers to data thatis sent onto an optical channel. If the MAC module sends a non-enablesignal to the optical module, the optical module still emits light in anuplink direction when a control signal TX_ENABLE of the optical modulehas a low level, namely, when the signal is a non-enable signal (whenthe control signal of the ONU is a non-enable signal, a time period inwhich the ONU is in a non-enable state may be regarded as “unauthorizedtime”). At this time, the MAC module sends the identity code of the ONUto the optical module, so that the OLT can detect the identity code ofthe ONU in the open uplink empty window or the empty timeslot, andtherefore, determines that the ONU corresponding to the identity code ofthe ONU is a rogue ONU.

(2) The optical module of the ONU obtains the identity code of the ONUfrom the optical module of the ONU.

When the MAC module of the ONU controls the optical module to emitlight, if the MAC module does not input a signal but the optical moduleis emitting light at this time, the optical module emits lightindependently without external control. In this case, the optical modulemay extract the identity code of the ONU from the optical module, andsend the identity code of the ONU. The identity code may bepre-configured by the system on the optical module. The OLT may detectthe identity code in the open uplink empty window or the empty timeslot,and if the identity code can be detected, the OLT may determine that theONU corresponding to the identity code is a rogue ONU.

The following specifically explains a relationship between “authorizedtime”, “unauthorized time”, “an open uplink empty window”, and “an emptytimeslot”.

The open uplink empty window refers to a window in which the OLT doesnot authorize an uplink bandwidth for any ONU, that is, in this emptywindow, the OLT requires all ONU not to emit light. The empty timeslotis aperture time between two adjacent uplink authorized bandwidths, andeach uplink authorized bandwidth is corresponding to authorized time ofone ONU. A reason for selecting the open uplink empty window or theempty timeslot as time for detecting the rogue ONU is: if the identitycode of the ONU is received within authorized time of a certain ONU,where the identity code of the ONU is sent by the ONU, normal data isoverlapped with data that carries the identity code, and the OLT may notidentity the identity code in the data; however, in the open uplinkempty window or the empty timeslot, an ONU that works properly sends nodata, and only a rogue ONU may send data, and therefore, data receivedby the OLT is data that carries an identity code of a rogue ONU, so thatan ONU corresponding to the identity code can be conveniently parsedout.

As shown in FIG. 2, a PON including an OLT and 3 ONUs (ONU1, ONU2, andONU3) is taken as an example. S1 is authorized time of the ONU1, F1 isunauthorized time of the ONU1, S2 is authorized time of the ONU2, F2 isunauthorized time of the ONU2, S3 is authorized time of the ONU3, F3 isunauthorized time of the ONU3, K is time of an open uplink empty window,and G is an empty timeslot. “Unauthorized time” of the ONU may also beunderstood as time when a control module (for example, an MAC module) ofthe ONU sends a non-enable signal to an optical module of the ONU tocause a low level of TX_Enable of the optical module of the ONU.

It can be known from the foregoing explanation that the optical moduleof the ONU may receive an identity code of the ONU when receiving a“non-enable” signal that is sent by the MAC module, where the identitycode of the ONU is sent by the MAC module; or, the optical module of theONU obtains the identity code that is pre-configured from the opticalmodule of the ONU. When the OLT opens an uplink empty window or an emptytimeslot, if a rogue ONU exists, the OLT may detect the identity code ofthe ONU, and may further determine that an ONU corresponding to theidentity code is a rogue ONU. If no data that carries the identity codeof the ONU is detected, it is determined that no ONU exists. Thedetection process does not affect a normal uplink service.

Through the method for detecting an ONU in this embodiment, the identitycode of the ONU is detected in the open uplink empty window or the emptytimeslot; and according to the identity code of the ONU, the ONUcorresponding to the identity code of the ONU is determined as a rogueONU, so that a rogue ONU is detected and determined quickly andaccurately, and therefore, an effect on an uplink service is reduced,and user satisfaction is improved.

Embodiment 2

This embodiment provides an optical network unit (ONU) 10. As shown inFIG. 3, the ONU includes an optical module 102, where the optical module102 includes an obtaining unit 1022, configured to obtain an identitycode of an ONU and a sending unit 1024, configured to send the identitycode of the ONU, where the identity code of the ONU is obtained by theobtaining unit, so that an OLT can detect the identity code of the ONUin an open uplink empty window or an empty timeslot.

The obtaining unit 1022 obtains the identity code of the ONU in twomanners: one is reading the identity code of the ONU from the opticalmodule 102; and the other is obtaining the identity code of the ONU froma control module of the ONU. For the second manner, the ONU may furtherinclude a control module 104.

The control module 104 is configured to send a non-enable control signaland the identity code of the ONU to the optical module. The controlmodule 104 may be an MAC chip or an MAC module of the ONU.

The obtaining unit 1022 of the optical module 102 is further configuredto receive the non-enable control signal and the identity code of theONU, where the non-enable control signal and the identity code of theONU are sent by the control module 104.

For a detailed obtaining process, reference may be made to thedescription in the first embodiment, which is not described here again.

The identity code of the ONU is a specific sequence optical channel codethat identifies the ONU.

Through the ONU in this embodiment, the ONU obtains the identity code ofthe ONU, and sends the identity code of the ONU, so that if a rogue ONUexists, the OLT can detect the identity code of the ONU in the openuplink empty window or the empty timeslot; and according to the identitycode of the ONU, determines an ONU corresponding to the identity code ofthe ONU as a rogue ONU. In this way, a rogue ONU is detected anddetermined quickly and accurately, and therefore, an effect on an uplinkservice is reduced, and user satisfaction is improved.

Embodiment 3

FIG. 4 shows an optical line terminal (OLT) 20. The OLT 20 includes adetecting module 202 and a processing module 204.

The detecting module 202 is configured to, in an open uplink emptywindow or an empty timeslot of the OLT, detect whether an identity codeof an optical network unit (ONU) is received.

The processing module 204 is configured to, when the detecting moduledetects the identity code of the ONU, determine that an ONUcorresponding to the identity code of the ONU is a rogue ONU.

The identity code of the ONU is a specific sequence optical channel codethat identifies the ONU.

Through the OLT in this embodiment, if the identity code of the ONU isdetected in the open uplink empty window or the empty timeslot,according to the identity code of the ONU, the ONU corresponding to theidentity code of the ONU may be determined as a rogue ONU. In this way,a rogue ONU is detected and determined quickly and accurately, andtherefore, an effect on an uplink service is reduced, and usersatisfaction is improved.

Embodiment 4

FIG. 5 shows a passive optical network (PON) system. The system includesan optical line terminal (OLT) 20 and at least one optical network unit(ONU) 10, where the ONU includes an optical module 102 (as shown in FIG.3).

The optical module 102 is configured to obtain an identity code of anONU, and send the identity code of the ONU; and

The OLT 20 is configured to receive the identity code of the ONU in anopen uplink empty window or an empty timeslot, and according to theidentity code of the ONU, determine that an ONU corresponding to theidentity code of the ONU is a rogue ONU.

The identity code of the ONU is a specific sequence optical channel codethat identifies the ONU.

The passive optical network system further includes an opticaldistribution network (ODN) 30, which includes a trunk fiber, a passiveoptical splitter, and a branch fiber. The ODN is configured to connectthe OLT 20 with the ONU 10. The OLT 20 is connected with the passiveoptical splitter through the trunk fiber. The optical splitterimplements point-to-multipoint optical power distribution, and isconnected to multiple ONUs through multiple branch fibers.

The ONU 10 may further include a control module 104 (as shown in FIG.3), which is configured to send a non-enable control signal and theidentity code of the ONU to the optical module. The obtaining unit 1022of the optical module 102 is further configured to receive thenon-enable control signal and the identity code of the ONU, where thenon-enable control signal and the identity code of the ONU are sent bythe control module 104 (for a detailed function of the ONU 10, referencemay be made to the second embodiment).

Through an optical network system in this embodiment, the ONU obtainsthe identity code of the ONU and sends the identity code of the ONU tothe OLT, so that if the identity code of the ONU is detected in the openuplink empty window or the empty timeslot of the OLT, it may bedetermined that a rogue ONU exists, and according to the identity codeof the ONU, the ONU corresponding to the identity code of the ONU mayfurther be determined as a rogue ONU. In this way, a rogue ONU isdetected and determined quickly and accurately, and therefore, an effecton an uplink service is reduced, and user satisfaction is improved.

It should be noted that, in this specification, terms like “first” and“second” are only used to differentiate one entity or operation fromanother, but are not necessarily used to indicate any practicalrelationship or order between these entities or operations. Moreover, aterm such as “include”, “contain” or any variation of the term means“including but not limited to”. Therefore, a process, method, object, ordevice that includes a series of elements not only includes theseelements, but also includes other elements that are not specifiedexpressly, or may further include inherent elements of the process,method, object or device. In the case that there are no morelimitations, in the context of a element that is specified by “includeone . . . ”, the process, method, object or device that includes aspecified element may include other identical elements.

The foregoing descriptions are merely exemplary embodiments of thepresent invention, but are not intended to limit the protection scope ofthe present invention. Any modification, equivalent replacement, orimprovement made without departing from the spirit and principle of thepresent invention shall fall within the protection scope of the presentinvention.

What is claimed is:
 1. A method for detecting an optical network unit(ONU), wherein, the method comprises: detecting an ONU identity code inan open uplink empty window or an empty timeslot; and determining thatan ONU corresponding to the ONU identity code is a rogue ONU accordingto the ONU identity code.
 2. The method according to claim 1, wherein:the ONU identity code is pre-configured and sent by an optical module ofthe ONU.
 3. The method according to claim 2, wherein: the ONU identitycode is a specific sequence optical channel code that identifies theONU.
 4. The method according to claim 1, wherein: the ONU identity codeis obtained and sent by an optical module of the ONU from a controlmodule of the ONU within unauthorized time.
 5. The method according toclaim 4, wherein: the ONU identity code is a specific sequence opticalchannel code that identifies the ONU.
 6. The method according to claim1, wherein: the ONU identity code is a specific sequence optical channelcode that identifies the ONU.
 7. An optical network unit, wherein theoptical network unit (ONU) comprises an optical module, and the opticalmodule comprises: an obtaining unit, configured to obtain an ONUidentity code; and a sending unit, configured to send the ONU identitycode, wherein the ONU identity code is obtained by the obtaining unit,so that an OLT can detect the ONU identity code in an open uplink emptywindow or an empty timeslot.
 8. The optical network unit according toclaim 7, wherein the ONU further comprises: a control module, configuredto send a non-enable control signal and the ONU identity code to theoptical module; and the obtaining unit of the optical module is furtherconfigured to receive the control signal and the ONU identity code,wherein the control signal and the ONU identity code are sent by thecontrol module.
 9. The optical network unit according to claim 8,wherein: the ONU identity code is a specific sequence optical channelcode that identifies the ONU.
 10. The optical network unit according toclaim 7, wherein: the obtaining unit is further configured to read theONU identity code, wherein the ONU identity code is stored in theoptical module.
 11. The optical network unit according to claim 10,wherein: the ONU identity code is a specific sequence optical channelcode that identifies the ONU.
 12. The optical network unit according toclaim 7, wherein: the ONU identity code is a specific sequence opticalchannel code that identifies the ONU.
 13. An optical line terminal,wherein the optical line terminal (OLT) comprises: a detecting module,configured to detect whether an ONU identity code is received in an openuplink empty window or empty timeslot of the OLT; and a processingmodule, configured to determine that an ONU corresponding to the ONUidentity code is a rogue ONU when the detecting module detects theidentity code of the ONU.
 14. The optical line terminal according toclaim 13, wherein: the ONU identity code is a specific sequence opticalchannel code that identifies the ONU.
 15. A passive optical networksystem, wherein: the system comprises an optical line terminal (OLT) andat least one optical network unit (ONU); the ONU comprises an opticalmodule; the optical module is configured to obtain an ONU identity code,and send the ONU identity code; and the OLT is configured to receive theONU identity code in an open uplink empty window or an empty timeslot,and determine that an ONU corresponding to the ONU identity code is arogue ONU according to the identity code of the ONU.
 16. The opticalnetwork system according to claim 15, wherein: the ONU identity code isa specific sequence optical channel code that identifies the ONU.